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Biomedical subjects

M Kitano

Publications and source records attributed to M Kitano.

At least 91 records · Page 5Linked to original sources
PubMed1998

Recurrence of unicystic ameloblastoma: a case report and review of the literature.

Unicystic ameloblastoma is believed to be less aggressive and responds more favorably to conservative surgery than the solid or multicystic ameloblastomas. We report a case of unicystic ameloblastoma that was initially treated by marsupialization and later by enucleation under suspicion of a dentigerous cyst. The neoplastic nature of the lesion became evident only when the enucleated material was available for histologic examination. Apart from an ameloblastomatous epithelial lining and luminal tumor nodules, the cystic tumor contained numerous tumor islands within its fibrous capsule. The lesion recurred 8 years after the enucleation. This case supports the view that the presence of tumor islands in the fibrous capsule may indicate a high risk of recurrence for unicystic ameloblastomas. Relevant diagnostic problems and choice of treatment are presented along with a review of the literature.

Ameloblastoma↗
PubMed1997

Augmented inhibitory effect of superoxide dismutase on superoxide anion release from macrophages by direct cationization.

Superoxide dismutase (SOD) was modified into cationized form (Cat-SOD) in order to enhance its pharmacological efficacy based on an electrostatic interaction. The inhibitory effect of Cat-SOD on superoxide anion release from inflammatory macrophages and its cellular interaction were studied in vitro. Cat-SOD exhibited an excellent inhibitory effect on superoxide anion release from the macrophages, and this effect surpassed those of native SOD and SOD modified with mannose (Man-SOD) which is taken up via mannose receptor-mediated endocytosis by macrophages. In the presence of colchicine, a microtubule-disruptive agent, the inhibitory effect of Cat-SOD was slightly impaired, whereas the effect of Man-SOD completely disappeared. The intracellular localization of fluorescein isothiocyanate-labeled SOD, Cat-SOD and Man-SOD observed by confocal laser microscopy supported the difference in their abilities to eliminate superoxide anions. The different sensitivities of Cat-SOD and Man-SOD to colchicine were also confirmed by the confocal laser microscopic images, suggesting their distinct intracellular trafficking pathways in the macrophages. In conclusion, Cat-SOD is desirable for its pharmacological activity, which is probably the result of its ability to be delivered to the vicinity of NADPH-oxidase which locates in the cell membrane and generates superoxide anions.

Animals↗
PubMed1997

Polymorphism of extracellular superoxide dismutase (EC-SOD) gene: relation to the mutation responsible for high EC-SOD level in serum.

Extracellular superoxide dismutase (EC-SOD) with amino acid substitution R213G generated by the nucleotide substitution 760C-->G in the heparin binding domain is responsible for the high EC-SOD level in serum. We identified the two DNA polymorphic sites in the coding region of EC-SOD gene related to the 760C-->G and determined the allele frequencies. The polymorphism were A and G at nucleotide position (nt.) 241 and C and T at nt. 280 near the N-terminal. The haplotype frequencies in Japanese were 241A280C: 0.45, 241G280T: 0.37, and 241G280C: 0.18. The haplotype of 241A280T did not exist. The mutation 760C-->G must occur on the allele having the haplotype of 241G280T.

Extracellular Space↗
PubMed1997

Glutathione S-transferase pi-class as a tumour marker in lingual preneoplastic and neoplastic lesions of rats and humans.

Immunocytochemical expression of the pi class glutathione S-transferase (GST) was investigated in preneoplastic and neoplastic lingual lesions in a 4-nitro-quinoline 1-oxide (4NQO)-induced rat genetic model [Wistar/Furth rats (WF) and Dark-Agouti rats (DA)] and in human surgical material [fibrous polyp, mild to moderate dysplasia, severe dysplasia, carcinoma in situ (CIS), squamous cell carcinoma (SCC)]. Two polyclonal antibodies raised against rat (GST-P) and human (GST-pi) antigens were used. In the rat model, DA and WF rats showed contrasting susceptibility to 4NQO, DA rats having a much higher tumour incidence and a significantly shorter survival time than WF rats. While the established lingual SCC in DA and WF rats all expressed GST-P, the number of GST-P+ foci in the preneoplastic lingual epithelium was significantly higher in DA (14.5 +/- 6.5) than in WF rats (5.5 +/- 2.6; P < 0.0001). In contrast, GST-pi epithelial staining in human specimens was more variable and the results overlapped in different groups. More frequent nuclear and/or basal cell staining was detected in severe dysplasia, CIS and SCC than in benign and mild to moderate dysplastic lesions. Although the pi class GST may be a useful marker for rat lingual carcinogenesis, its value in clinical applications is unclear. GST-pi staining patterns and their distribution may be helpful in identifying high-risk lingual lesions in humans.

4-Nitroquinoline-1-oxide↗
PubMed1997

Lobectomy with extended lymph node dissection by video-assisted thoracic surgery for lung cancer.

BACKGROUND: Between September 1992 and September 1996, we performed 88 VATS (video-assisted thoracic surgery) lobectomies and two VATS pneumonectomies. METHODS: The indications for surgery were 68 cases of lung cancer, nine cases of bronchiectasis, six cases of tuberculosis, and seven cases of benign lesions. Of the 68 cases of lung cancer, 36 were treated by VATS lobectomy with extended lymph node dissection for clinical stage I lung cancer, making full use of recently developed devices for thoracoscopic surgery, such as roticulating endoscissors, miniretractors, endoclips, and harmonic scalpels. RESULTS: Twenty-four lymph nodes were resected on average (range, 10 to 51) by VATS. This number was comparable to lymph nodes resected in open thoracotomy during the same period. Among the 36 patients who underwent extended lymph node dissection, 20 showed no lymph node metastasis postoperatively (stage I), while 16 had N1 or N2 cancer. All patients with stage I cancer have survived 4 to 36 months (median: 17 months) with no signs of recurrence. CONCLUSIONS: This survival of stage I lung cancer after VATS is comparable to that of open thoracotomy. We thus believe that VATS lobectomy with extended lymph node dissection can be an alternative to standard posterolateral thoracotomy for stage I lung cancer.

Adenocarcinoma↗
PubMed1997

Intra-articular fibroma of tendon sheath in the temporomandibular joint.

Fibroma of tendon sheath is an uncommon soft tissue tumor. The first case involving the temporomandibular joint is reported here. The patient presented with chronic clicking, pain, and swelling of the right temporomandibular joint associated with restricted jaw opening. Histologic, immunocytochemical, and ultrastructural features of the intra-articular tumor were identical to fibroma of tendon sheath. The variability of symptoms and the diagnostic problems presented by this tumor are discussed.

Actins↗
PubMed1997

Calcium and silicon from bioactive glass concerned with formation of nodules in periodontal-ligament fibroblasts in vitro.

Previously, the authors reported that bioactive glass promoted formation of nodules in cultured periodontal-ligament fibroblasts and high concentrations of calcium and silicon were detected in the culture medium. Herein, the effects of bioactive glass, calcium alone and calcium and silicon for formation of nodules on the periodontal-ligament fibroblasts are examined. The cells were cultured with bioactive glass, without bioactive glass, calcium and silicon, with calcium alone and with calcium and silicon. The cell growth, alkaline-phosphatase activity, amount of pro-collagen type I and the number of nodules were measured periodically until the 21st day. The cell growth rate with calcium and silicon was the highest, however the rate with bioactive glass and calcium alone were similar to that without them. The alkaline-phosphatase activity and the amount of pro-collagen showed peaks at the 11th day. At the peak, the alkaline-phosphatase activity with bioactive glass or calcium and silicon, and the pro-collagen with bioactive glass was higher than without them. The number of nodules with bioactive glass, calcium alone or calcium and silicon was greater than without them. These findings suggested that the combination of calcium and silicon released from bioactive glass was concerned with the formation of nodules on the periodontal-ligament cells.

Alkaline Phosphatase↗
PubMed1997

Carcinogenicity of methylurea or morpholine in combination with sodium nitrite in rat multi-organ carcinogenesis bioassay.

For carcinogenic risk assessment of combinations of N-nitroso precursors in man, the effects of feeding methylurea (MU) or morpholine (Mor) plus sodium nitrite (NaNO2) were investigated using a multi-organ carcinogenesis model. In experiment 1, to initiate multiple organs, groups of 10 or 20 male F344 rats were treated with 6 carcinogens targeting different organs. Starting a week after completion of this initiation phase, animals were given 0.1% MU or 0.5% Mor in their food and/or 0.15% NaNO2 in their drinking water for 23 weeks. The induction of tumors and/or preneoplastic lesions in the forestomach and esophagus was significantly increased in the group receiving MU plus NaNO2. The numbers and areas of liver glutathione S-transferase placental form (GST-P)-positive foci were significantly elevated with MU or Mor plus NaNO2. Experiment 2 was conducted to assess formation of N-nitroso compounds in the stomach, and to detect DNA adduct generation in target organs by immunohistochemical staining. Groups of 5 or 14 animals were starved overnight, then given 0.4% MU or 2.0% Mor in the diet, or basal diet alone for 1 h. Then NaNO2 or distilled water was given intragastrically. The mean gastric N-methyl-N-nitrosourea yield in the MU plus NaNO2 group was 7700 micrograms at 2 h after combined administration. The mean N-nitrosomorpholine yield in the group given Mor plus NaNO2 was 6720 micrograms. Immunohistochemically, N7-methyldeoxyguanosine-positive nuclei were evident in the forestomach epithelium at 8 h after the combination treatment with MU plus NaNO2.

Administration, Oral↗
PubMed1997

Experimental endocarditis induction and platelet aggregation by Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius.

A total of 18 'Streptococcus milleri' strains including the ATCC type strains of Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedius were compared with Streptococcus oralis ATCC10557 for their ability to induce infective endocarditis in catheterized rats. Three days after intravenous injection of 10(8) colony-forming units all 8 S. anginosus strains tested produced infective vegetations and bacteremia in almost all rats whereas 5 S. constellatus strains and the S. oralis strain produced infective vegetations and bacteremia less frequently and 5 S. intermedius strains only occasionally. The vegetations infected with the S. anginosus strains harbored microbial cells in significantly higher numbers that those with the other strains. No strong correlation was found between the endocardial infectivity and platelet-aggregating capacity of these strains. The platelet-aggregating strains were members of the Lancefield groups F and G or ungroupable but not of group A or C.

Animals↗
PubMed1997

Myxoglobulosis in an extravasation mucocele of the lower lip.

A case of extravasation mucocele showing an unusual intraluminal globular organization of the mucous content is described. The cystic lesion was obtained from the lower lip of a 10-year-old Japanese girl and presented as a painless swelling of 1 year duration. Histologically, the cyst cavity was filled with round globules and encapsulated by a granulation tissue wall devoid of a lining epithelium. To our knowledge this peculiar histological pattern has not been previously described in an oral mucocele. Clinicopathological features of 'myxoglobulosis of the appendix', a morphological variant of appendiceal mucocele, appear to be related to the present case.

Child↗
PubMed1997

Effects of sucralfate on acute gastric mucosal injury and gastric ulcer induced by ischemia-reperfusion in rats.

We have revealed that acute gastric mucosal injury induced by a single ischemia-reperfusion (I-R) treatment develops into an ulcerative lesion within a few days. In the present studies, we examined the effects of oral administration of sucralfate on gastric damage induced by I-R. Sucralfate (1-100 mg/kg, 15 min before I-R) significantly reduced the total erosion area observed immediately after I-R. A high dose of sucralfate (30-100 mg/kg) inhibited the increase in the thiobarbituric acid-reactive substances, an index of lipid peroxidation, induced by I-R, although a low dose of it failed. When sucralfate (30 mg/kg, once a day) was orally administered after I-R, it prevented mucosal damage from developing into gastric ulcers: the total area of the ulcers was significantly reduced compared to that without sucralfate administration 72 h after I-R. High concentrations of sucralfate (3-10 mg/ml) reduced the superoxide radicals generated by leukocytes or xanthine-xanthine oxidase, and protected erythrocyte membrane ghosts against lipid peroxidation induced by hydrogen peroxide and Fe2+ in vitro. These results indicate that sucralfate may prohibit both the generation of acute gastric mucosal injury and its progression to ulcer induced by I-R, probably due to a cytoprotective action on the mucosal surface. However, the protective mechanism may involve an inhibitory action on superoxide and hydroxyl radicals at high doses.

Animals↗
PubMed1997

Effects of cimetidine on acute gastric mucosal injury induced by ischemia-reperfusion in rats.

We investigated the effects of cimetidine on acute gastric mucosal injury induced by ischemia-reperfusion in rats. Under pentobarbital anesthesia, the celiac artery was clamped for 30 min and reperfused for 60 min. Cimetidine, famotidine and omeprazole caused a dose-dependent suppression in the total area of erosions that were induced by ischemia-reperfusion. Whereas, none of them inhibited the increase in thiobarbituric acid-reactive substances in the stomach, as an index of lipid peroxidation. The inhibitory effect of intraperitoneally administered cimetidine on mucosal damage was abolished by continuous luminal perfusion with HCl solution (pH 1.5, 1 ml/min) during ischemia-reperfusion, while luminal perfusion with the solution containing HCl and cimetidine (3 mmol/l) significantly reduced the total area of erosions compared to luminal perfusion with HCl solution alone. Cimetidine (3 mmol/l) inhibited hydroxyl radical-induced lipid peroxidation of human erythrocyte membranes by 60% in vitro. These results indicate that cimetidine possesses a protective effect against acute gastric mucosal injury induced by ischemia-reperfusion not only due to the suppression in gastric acid secretion, but also due to the antioxidant action when it is present at a high concentration in the intragastric environment.

Animals↗
PubMed1997

A case of unilateral diaphragmatic eventration treated by plication with thoracoscopic surgery.

A 56-year-old woman underwent plication with U-stitches by thoracoscopic surgery for left diaphragmatic eventration. Marked improvement in left lung expansion, normalization of the position of the left diaphragm on chest radiograph, and improvement of pulmonary function and dyspnea on exertion have been maintained for 2 years. Plication for diaphragmatic eventration should be performed with minimally invasive surgery.

Diaphragmatic Eventration↗